Kim Jong Un is a top suspect in his half brother’s death. But questions abound.

KUALA LUMPUR, Malaysia — Feb. 16 is always a glorious day on the North Korean calendar. Known as the “Day of the Shining Star,” it marks the anniversary of the birth of Kim Jong Il, the country’s second-generation leader.

This year, as usual, wreaths were laid Thursday at statues of Kim Jong Il and his father, North Korea’s “Eternal President,” Kim Il Sung. There were also parades and figure skating and synchronized swimming and displays of the flowers known to the rest of us as begonias but to North Koreans as Kimjongilia.

The North’s third-generation leader, Kim Jong Un, cut a solemn figure as he bowed at his father’s tomb and presided over a meeting of Communist Party apparatchiks.

But was that look of gravity a mark of respect for his deceased father? A sign of shock at the sudden death this week of his estranged older half brother? Or the steely face of a man who will stop at nothing to hold on to power?

For South Korea’s often-unreliable intelligence service and some analysts in China, Kim Jong Un is suspect No. 1 in the apparent assassination this week of Kim Jong Nam, who was the oldest son of Kim Jong Il and had been living in a kind of exile for the past 15 years.

This image obtained Feb. 16 from the Indonesian news portal Kumparan shows the photo in the passport of Siti Aishah, 25, an Indonesian woman suspected of involvement in Kim Jong Nam’s killing in Kuala Lumpur on Monday. (Kumparan via AP)

North Korea has a history of state-ordered assassinations, including an attempt — involving a poison needle disguised as a pen — to kill a defector-turned-activist in South Korea as recently as 2011.

Malaysian police have arrested two people accused of direct involvement in the brazen attack on Kim Jong Nam at Kuala Lumpur airport Monday — the women alleged to have carried out the poisoning, one apparently from Vietnam and the other from Indonesia — and have detained the Indonesian woman’s Malaysian boyfriend to help them with their inquiries.

But so many questions remain. Why would Kim Jong Un want to kill a half brother who, apart from one statement in 2010 questioning North Korea’s hereditary succession system, had shown no political ambitions?

Why would he have him killed just days before an auspicious anniversary? And why would North Korea deviate from its practice of using elite agents for such tasks, instead allegedly sending foreign women so ill equipped for the task that they didn’t even know to flee?

One theory: Kim Jong Un, who was only 27 when he became leader and had little government or military experience, is still getting rid of potential rivals.

Like other dictators before him, he has overseen the dispatch, temporarily or permanently, of people who could challenge him for the leadership of his country. He most notably had his uncle — and Kim Jong Nam’s mentor — executed in late 2013 for amassing too much power.

(Reuters)

He has also overseen the purging or execution of a whole raft of senior officials, including his defense minister, his deputy education and construction ministers and, just this month, his apparently demoted minister of state security.

A report by the South Korean intelligence service’s think tank at the end of last year estimated that Kim ordered the executions of 340 people, including 140 senior officials, in his first five years in power.

Kim Jong Un showed from the get-go that he would sort out the loyal from the wavering, said Bruce Bueno de Mesquita, a political scientist at New York University and co-author of “The Dictator’s Handbook.”

“The execution of his uncle sent a message: ‘I’m sorting out my allies and clearing out the rest,’ ” Bueno de Mesquita said. “He has been well trained, and he has good intuition about what a person running a place like North Korea needs to do.”

But Christopher Green, a North Korea scholar at the Netherlands’ Leiden University, said Kim Jong Nam was not a threat to his younger brother’s legitimacy.

“He lived in quiet exile abroad, whereas Kim Jong Un was Kim Jong Il’s anointed heir,” Green said. “Kim Jong Nam was never going to be an alternative power center, and power doesn’t get consolidated, per se. The process has no start or end. It is a constant battle to stay on top.”

Kim Jong Un has defied predictions of his imminent demise, in December marking five years at the helm, a period characterized by relatively strong growth and tangible advances in the North’s nuclear and missile programs.

Meanwhile, his older half brother appeared to be living the good life. He had been based in Macau and Beijing for well over a decade — apparently having wives and families in both places — liked visiting casinos and was said to have playboy tendencies.

Some analysts, urging skepticism, say it is more likely that Kim Jong Nam ran afoul of the underworld in Southeast Asia than that Kim Jong Un ordered the hit. But in the absence of clear evidence either way, opinion is coalescing around that second idea.

Because even if Kim Jong Nam didn’t have grand designs for his future, China did.

Relations between Beijing and Pyongyang have worsened dramatically in the past five years, with Kim Jong Un showing obvious disdain for Chinese President Xi Jinping and the Chinese appearing to view the young leader as erratic. This has led to speculation that Beijing has been keeping Kim Jong Nam on standby in case it needs to install another, more China-friendly Kim in Pyongyang.

Wang Weimin, an international-relations specialist at Fudan University in Shanghai, said China had security measures in place to protect Kim Jong Nam from North Korean agents, even though it had long recognized he was not leadership material.

“China did not have huge expectations for him but provided protection for him and his family,” Wang said, “because China had political sympathy” for him.

Wang estimated the likelihood that Kim Jong Un had ordered his older brother’s assassination at 80 percent. “It is not surprising that he wants to clean out anybody threatening to his reign,” he said.

Officials in China also seem to be leaning toward the theory that Kim Jong Un ordered the killing.

An editorial in the state-run Global Times said that Beijing would join in expressions of international condemnation if Malaysian authorities conclude that Kim Jong Nam was assassinated. “Human civilization is now in the 21st century, and such a savage and outdated political device should be cast into the museums of history,” it read.

Noting that the investigation was still underway, it said speculation was nevertheless “sharply pointed” at Pyongyang.

“Such speculation is severely damaging to North Korea’s reputation on the international stage,” the editorial said.